I laughed. I cried. I found it informative. I noticed a few places where it could have been better.

We recorded the video in response to a tweet from one of our Twitter followers, and the off-the-cuff dialog wound up being somewhere in between “accessible, informative and funny” and “overly detailed, too long and obviously improvised.” Because there aren’t many people who want to listen to two guys give a 15-minute presentation on IP addresses when they could be watching a Songified review of Five Guys Burgers and Fries or an epic data center tour, I thought I’d dilute the information from the video into a quick blog post that spells out some of the major distinctions between IPv4 and IPv6 so you can scan it, interject your own “witty” banter and have your favorite YouTube viral video playing in the background.

IP Address Overview

An IP address is like a telephone number or a street address. When you connect to the Internet, your device (computer, smartphone, tablet) is assigned an IP address, and any site you visit has an IP address. The IP addressing system we’ve been using since the birth of the Internet is called IPv4, and the new addressing system is called IPv6. The reason we have to supplement the IPv4 address system (and ultimately eclipse it) with IPv6 is because the Internet is running out of available IPv4 address space, and IPv6 provides is an exponentially larger pool of IP addresses … Let’s look at the numbers:

• Total IPv4 Space: 4,294,967,296 addresses
• Total IPv6 Space: 340,282,366,920,938,463,463,374,607,431,768,211,456 addresses

Even saying the IPv6 space is “exponentially larger” doesn’t really paint the picture of the difference in size.

IPv4 Addresses

To understand why the IPv4 address space is limited to four billion addresses, we can break down an IPv4 address. An IPv4 address is a 32-bit number made up of four octets (8-bit numbers) in decimal notation, separated by periods. A bit can either be a 1 or a 0 (2 possibilities), so the decimal notation of an octet would have 2⁸ distinct possibilities — 256 of them, to be exact. Because we start numbering at 0, the possible values of one an octet in an IPv4 address go from 0 to 255.

Examples of IPv4 Addresses: 192.168.0.1, 66.228.118.51, 173.194.33.16

If an IPv4 address is made up of four sections with 256 possibilities in each section, to find the total number of possibilities in the entire IPv4 pool, you’d just multiply 256*256*256*256 to get to the 4,294,967,296 number. To look at it another way, you’ve got 32 bits, so 2³² will get you to the same total.

IPv6 Addresses

IPv6 addresses are based on 128 bits. Using the same math as above, we can take 2¹²⁸ and find the total IPv6 address pool (which I won’t copy again here because it takes up too much space). Because the IPv6 pool is so much larger than the IPv4 pool, it’d be much more difficult to define the space in the same decimal notation … you’d have 2³² possibilities in each section.

To allow for that massive IPv6 pool to be used a little more easily, IPv6 addresses are broken down into eight 16-bit sections, separated by colons. Because each section is 16 bits, it can have 2¹⁶ variations (65,536 distinct possibilities). Using decimal numbers between 0 and 65,535 would still be pretty long-winded, so IPv6 addresses are expressed with hexadecimal notation (16 different characters: 0-9 and a-f).

Example of an IPv6 Addresses: 2607:f0d0:4545:3:200:f8ff:fe21:67cf

That’s still a mouthful, but it’s a little more manageable than the decimal alternatives.

CIDR Slash (/) Notation

When people talk about blocks of IP addresses, they generally use CIDR Slash (/) Notation where the block might look like this: 192.0.2.0/24 … When you glance at that number, you might assume, “Okay, so you have 192.0.2.0 through 192.0.2.24,” but CIDR notation is not showing you the range of addresses, it’s telling you the size of the “network” part of the allocation.

IP addresses are made up two parts — the network and the host. The “network” part of the address tells us the number of bits that stay the same at the beginning of the block of IPs, while the “host” part of the address are the bits that define the different possibilities of IP addresses in the block. In CIDR notation, a /24 is telling us that the first 24 bits of the address are defined by the network, so we have 8 bits (32 total bits minus 24 network bits) in the host — 2⁸ is 256 distinct addresses. The 192.0.2.0/24 IPv4 address block includes 192.0.2.0 to 192.0.2.255.

IPv4 address blocks can be as large as a /8 (given to regional registries like ARIN and APNIC), and they can be as small as a /32 (which is a single IP address).

Why Provision So Many IPv6 Addresses?

When SoftLayer provisions an IPv6 address block on a server, we give a /64 block of IPv6 addresses … Or 18,446,744,073,709,551,616 IPv6 addresses to each server. That number seems excessive, but the /64 block size is the “smallest” IPv6 allocation block.

Providers like SoftLayer are allocated /32 blocks of IPv6 addresses. The difference between a /32 and a /64 is 32 bits (2³²) … Bonus points if you can remember where you’ve seen that number before. What that means is that SoftLayer is given a block of IP addresses so large that we could provision 4,294,967,296 /64 blocks of IPv6 addresses … Or put more remarkably: In one /32 block of IPv6 space, there are the same number of /64 blocks of IPv6 addresses as there are TOTAL IPv4 addresses.

So while it’s pretty impossible to use a full /64 of IPv6 addresses on a server, it’s equally difficult for SoftLayer to burn through its /32 block.

So Now What?

IPv4 space is running out quickly. If your site isn’t running a dual-stack IPv6 configuration yet, it’s possible that you’re going to start missing traffic from users who are only able to access the Internet over IPv6 (which is not backwards compatible with IPv4). If your Internet Service Provider (ISP) doesn’t support IPv6 yet, you won’t be able to access websites that are broadcast only with IPv6 addresses.

The percentage of instances of each of those cases is relatively small, but it’s only going to get larger … And it only takes one missed customer to make you regret not taking the steps to incorporate IPv6 into your infrastructure.

-@khazard

What’s all of this fuss about the IPv6 transition about? The simplest way to explain the situation is that the current Internet can stay working as it does, using IPv4 addresses, forever … if we’re okay with it not growing any more. If no more homes and businesses wanted to get on the Internet, and no more new phones or tablets were produced, and no more websites or applications were created. SoftLayer wouldn’t be able to keep selling new servers either. To prevent or lose that kind of organic growth would be terrible, so an alternative had to be created to break free from the limitations of IPv4.

The long-term goal is to migrate the entire Internet to the IPv6 standard in order to eliminate the stifling effect of impending and inevitable IP address shortages. It is estimated that there are roughly 2.5 billion current connections to the Internet today, so to say the transition has a lot of moving parts would be an understatement. That complexity doesn’t lessen the urgency of the need to make the change, though … In the very near future, end-users and servers will no longer be able to get IPv4 connections to the Internet, and will only connect via IPv6.

The primary transition plan is to “dual-stack” all current devices by adding IPv6 support to everything that currently has an IPv4 address. By adding native IPv6 functionality to devices using IPv4, all of that connectivity will be able to speak via IPv6 without transitional technologies like NAT (Network Address Translation). This work will take several years, and time is not a luxury we have with the dwindling IPv4 pool.

Like George mentioned in a previous post, I see World IPv6 Launch day as a call-to-action for a “game changer.” The IPv6 transition has gotten a ton of visibility from some of the most recognizable names on the Internet, but the importance and urgency of the transition can’t be overstated.

So, what does that mean for you?

To a certain extent, that depends on what your involvement is on the Internet. Here are a few steps everyone can take:

• Learn all you can about IPv6 to prepare for the work ahead. A few good books about IPv6 have been published, and resources like ARIN’s IPv6 Information Wiki are perfect places to get more information.
• If you own servers or network equipment, check them for IPv6 functionality. Upgrade or replace any software or devices to ensure that you can deliver native IPv6 connectivity end-to-end without any adverse impact to IPv6 users. If any piece of gear isn’t IPv6-capable, IPv6 traffic won’t be able to pass through your network.
• If you are a content provider, make your content available via IPv6. This starts with requesting IPv6 service from your ISP. At SoftLayer, that’s done via a zero-cost sales request to add IPv6 addresses to your VLANs. You should target 100% coverage for your services or applications — providing the same content via IPv6 as you do via IPv4. Take an inventory of all your DNS records, and after you’ve tested extensively, publish AAAA records for all hostnames to start attracting IPv6 traffic.
• If you are receiving Internet connectivity to your home or business desktops, demand IPv6 services from your upstream ISP. Also be sure to check your access routers, switches and desktops to ensure they are running the most recent code with stable IPv6 support.
• If you are running equipment such as firewalls, load balancers, IDS, etc., contact your vendors to learn about their IPv6 support and how to properly configure those devices. You want to make sure you aren’t limiting performance or exposing any vulnerabilities.

Starting now, there are no more excuses. It’s time to get IPv6 up and running if you want to play a part in tomorrow’s Internet.

-Dani

With IPv6 Day serving as a “test run,” we confirmed a lot of what we know about IPv6 compatibility and interoperability with deployed systems throughout the Internet, and we even learned about a few areas that needed a little additional attention. Access troubles for end-users was measured in fractions of a percentage, and while some sites left IPv6 running, many of them ended up disabling the AAAA IPv6 records at the end of the event, resuming their legacy IPv4-only configuration.

We’re past the “testing” phase now. Many of the IPv6-related issues observed in desktop operating systems (think: your PCs, phones, and tablets) and consumer network equipment (think: your home router) have been resolved. In response – and in an effort to kick IPv6 deployment in the butt – the same businesses which ran the 24-hour field test last year have committed to turning on IPv6 for their content and keeping it on as of 6/6/2012.

But that’s not all, folks!

In the past, IPv6 availability would have simply impacted customers connecting to the Internet from a few universities, international providers and smaller technology-forward ISPs. What’s great about this event is that a significant number of major broadband ISPs (think: your home and business Internet connection) have committed to enabling IPv6 to their subscribers. June 6, 2012, marks a day where at least 1% of the participating ISPs’ downstream customers will be receiving IPv6 addresses.

While 1% may not seem all that impressive at first, in order to survive the change, these ISPs must slowly roll out IPv6 availability to ensure that they can handle the potential volume of resulting customer support issues. There will be new training and technical challenges that I suspect all of these ISPs will face, and this type of approach is a good way to ensure success. Again, we must appreciate that the ISPs are turning it on for good now.

What does this mean for SoftLayer customers? Well the good news is that our network is already IPv6-enabled … In fact, it has been so for a few years now. Those of you who have taken advantage of running a dual-stack of IPv4 and IPv6 addresses may have noticed surprisingly low IPv6 traffic volume. When 6/6/2012 comes around, you should see that volume rise (and continue to rise consistently from there). For those of you without IPv6 addresses, now’s the time to get started and get your feet wet. You need to be prepared for the day when new “eyeballs” are coming online with IPv6-only addresses. If you don’t know where to start, go back through this article and click on a few of the hyperlinks, and if you want more information, ARIN has a great informational IPv6 wiki that has been enjoying community input for a couple years now.

The long term benefit of this June 6th milestone is that with some of the “big guys” playing in this space, the visibility of IPv6 should improve. This will help motivate the “little guys” who otherwise couldn’t get motivated – or more often couldn’t justify the budgetary requirements – to start implementing IPv6 throughout their organizations. The Internet is growing rapidly, and as our collective attentions are focused on how current legislation (SOPA/PIPA) could impede that growth, we should be intentional about fortifying the Internet’s underlying architecture.

-Dani

On July 14, I was honored to speak at IPv6 2011: The Time is Now! about how technology is speeding up IPv4 exhaustion and what the transition to IPv6 will mean for content providers. Since the session afforded me a great opportunity to share a high level overview of how I see the IPv4-to-IPv6 transition (along with how SoftLayer has prepared), it might be interesting to the folks out there in the blogosphere:

As time goes by, these kinds of discussions are going to get less theoretical and more practical. The problem with IPv4 is that the entire world is about to run out of free space. The answer IPv6 provides is an allocation pool that is not in danger of exhaustion. The transition from IPv4 to IPv6 isn’t as much “glamorous” as it is “necessary,” and while the squeeze on IPv4 space may not affect you immediately, you need to be prepared for the inevitability that it will.

-@wcharnock

It’s easy to get lost in a sea of numbers when you start talking about IPv4 and IPv6 address space. With the exhaustion of IPv4 address space and the big push toward IPv6, everyone’s talking about address blocks, usage justification and dual stack compatibility, but all of those conversations presuppose a certain understanding of why IP addresses are the way they are. Someone can say, “The IPv6 pool is exponentially larger than the IPv4 pool,” but that statement needs a little context when you hear that providers like SoftLayer are provisioning a free /64 IPv6 allocation of 18,446,744,073,709,551,616 addresses to a single server. If the entire IPv4 pool on the Internet is 4,294,967,296 addresses and we’re giving away that many IPv6 addresses to a single server, a simple question logically follows:

Are the Internet authorities being irresponsible when they’re allowing such huge numbers of IPv6 addresses to be assigned to individual servers without a demonstrated need for that many addresses? Will this “wastefulness” lead to another IP address pool depletion in our lifetime? These questions are completely legitimate, and they’re much easier to explain in a visualized format than they are if we answered them line-by-line in text:

The video duration might seem intimidating, especially if you consider that all 15 minutes are spent talking about IP addresses (Woohoo!), but there’s a lot of information, and we did our best to break it down to simple pieces that logically follow each other to help you get the full picture of the world of IP addresses. We explain what CIDR Slash (/) Notation (where you see IP address blocks written as “192.0.2.0/24″), and we offer a simple trick to calculate the number of distinct addresses available in a given IPv4 block. There’s a fair amount of witty (and not-witty) banter and at least one use of the word “ridonkulous,” so if you enjoyed the DC Construction video commentary, you’ll get a kick out of this one too.

Toward the end of the video, we speak directly to why SoftLayer is able to give a /64 of IPv6 addresses to every server and what that means for the future of the IPv6 space.

Fun Fact: SoftLayer IP Address Space*

• IPv4: 872,448 Addresses
• IPv6 (/32): 79,228,162,514,264,337,593,543,950,336 Addresses

*Does not include IP space assigned to The Planet

Did the video help you wrap your mind around the differences between IPv4 and IPv6? Do you have any more questions about the differences between the two or how SoftLayer is approaching them?

-@khazard

Being down the line from ARIN, SoftLayer’s networking department has to ensure we abide by all updated ARIN policies when we issue IPv4 addresses from our available pool in order to remain eligible to receive additional resource allocations. In addition to policy compliance, we are also focused on IPv4 conservation methods such as those referenced in RFC2050. Accordingly, we’ve made improvements to the way that we handle IPv4 requests to better streamline the process of collecting and reviewing usage and justification details.

Every SoftLayer server comes with one public IPv4 address, and until recently was assigned 4 additional IPs (/30) statically routed to that server. Our first step of IP conservation took place earlier this year, when we ceased the practice of automatically assigning the 4 additional IPs, and only issued them by customer request.

As we move forward, were trying to be as transparent with our customers about the IPv4 justification process as we can, so we’re letting you know that additional justification requirements have been imposed on all ISPs by ARIN, and the best way we can meet those requirements is to have our customers follow the same guidelines. Being SoftLayer, we’re doing what we can to automate and streamline the IPv4 justification process where possible, and are therefore implementing changes in the ordering system. Beginning on June 1, you will now be presented with a brief questionnaire whenever requesting additional IPv4 addresses. We must collect the requester’s contact details, number of IPs that are expected to be used immediately and within the next year, as well as a brief description of how the IPs will be used. What happens next depends on the information you have provided as well as the current IP usage on your account: either the request is automatically approved and fulfilled, or a ticket is spawned for additional manual review by one of the folks in our networking team.

When a ticket is spawned for our network folks, we will get back to you within one business day, and let you know whether we need additional details from you in order to consider the request. These manual reviews will take additional time, depending on the size and complexity of request, as well as the quality of information provided. Please be prepared that there will be some cases where we will not be able to approve a request, such as when name-based virtualization can be used for IP conservation, or when services such as SEO, email campaigns, or VPN termination are the intended use for the additional IPv4 addresses.

If you’re familiar with SoftLayer’s previous method of ordering additional IPv4 addresses, you might feel like we’re making you jump through hoops. These “hoops” are not intended to make the process arbitrarily more difficult. Rather, they’re being put in place specifically to make sure we’re in the best position possible to meet customer demands with our current IPv4 allocations, and get additional allocations from ARIN before they are completely depleted.

The ISPs that have no problems giving away IPv4 addresses right now without more stringent review are also going to be the providers that have the hardest time getting additional IPv4 blocks from ARIN, and therefore will have a hard time fulfilling future customer needs. At SoftLayer we are going by the philosophy that the more cautiously we approach IPv4 depletion by justifying our customers’ needs for each IPv4 address, the longer our IPv4 pool will last to meet those needs.

This is a good opportunity to mention IPv6 as the long-term solution for IPv4 address depletion. The sooner that the public Internet becomes fully IPv6-enabled, the better off the resource constraint will become. The SoftLayer network is enabled for IPv6, and you may place an order for 18.4 quintillion free IPv6 addresses for your server via our web portal today!

-Dani

Are we in a “The sky is falling!” situation yet? How can customers put pressure on their ISPs and software providers to add IPv6 support? How long with ARIN and SoftLayer have IPv4 addresses to give out now that IANA has released their entire free pool? Here’s my take:

This video was recorded while Kevin was standing outside the Moscone Center in San Francisco at GDC 2011 over a mobile hotspot connection, so the video quality suffered a little. To silence the street noise, Kevin muted his side of the conversation as I spoke.

-Will

Rather than bore you with bullet points about what I shared, I thought it might be easier to bring you into the room so you can hear the whole session yourself:

Thanks for the opportunity, Parallels! We’re already looking forward to next year.

-@lavosby

As I alluded in ISOC’s press release, SoftLayer is a hosting provider, but we aren’t going to be an effective resource for our customers if we don’t adopt the newest technologies and platforms for future growth. Because we’ve built our business around that idea, you won’t see many substantial changes when June 8 rolls around … We were a little ahead of the curve in December 2008 when we began providing native IPv6 support to our publicly available services. The point of this Internet-wide event is not about getting there first, though … It’s about everyone getting there.

What does World IPv6 day mean to you? Probably little to nothing in the short-run. While there’s a unanimous sense of urgency to be prepared, the real deadline is still a little ways into the future. If you’re a SoftLayer customer, it’s pretty easy for you to take part in your own World IPv6 Day: Provision your free IPv6 /64 on your server and start using them.

I encourage you to set goals for IPv6 functionality for the near future so you don’t find yourself scrambling for a solution when you can’t get any new IPv4 addresses. Don’t let the fact that ARIN still has 5.20 IPv4 /8s in aggregate lull you into inaction … The well will run dry, and the sooner you’re ready for it, the better. Would your business be ready to flip the switch to IPv6 on June 8?

-Will

Luckily, a lot of people have been hard at work to mitigate the impending Internet crisis. IP version 6 (IPv6) is on the horizon and is already supported by most modern internet enabled devices. If you’re like me, the fact that we went from IPv4 to IPv6 might make you wonder, “What happened to IPv5?”

The powers that be didn’t decide to rid the number system of the number five because of its mixture of curves and right angles, and it wasn’t because they only wanted to use round numbers. IP version 5 (IPv5) was a work in progress and part of a family of experimental protocols by the name of ST (Internet Stream Protocol). ST and later ST-II were connection-oriented protocols that were intended to support the efficient delivery of data streams to applications that required guaranteed data throughput.

An ST packet looks very similar to its IPv4 sibling, and both use the first 8 bits to identify a version number. IPv4 uses those 8 bits to identify IPv4 packets, and ST used the same 8 bits to identify IPv5 packets. Since “version 5″ was spoken for, the next iteration in IP advancement became version 6.

If you’ve been around the SoftLayer blog for a while, you already know a fair bit about IPv6, but you’re probably wondering, “What’s next?” How do you actually start using IPv6 yourself?

1. Get a Block of IPv6 Addresses

Lucky for you, the SoftLayer platform is IPv6 ready, and we’re already issuing and routing IPv6 traffic. Obtaining a block of public IPs from us is as easy as logging into the portal, pulling up the hardware page of a server and ordering a /64 block of IPv6 IPs for $4/mo per subnet ($10 if you want a portable subnet)!

For those of you that have ordered IPs from us in the past, IPv4 addresses are usually $0.50-$1.00 each. To get a /64 of public static IPv6 addresses, it’s a whopping $0.00 for the entire range. So just how many IPs is in a /64? 256? Try again. 512? Keep going. 1 Million? You’re still cold. Let’s try 18.4 quintillion. For those that understand scientific notation better, that is 1.84 x 10¹⁹. If you just want to see the number written in long form, it’s 18,446,744,073,709,551,616 IP addresses. That allocation should probably tide you over for a little while.

2. Make Sure Your Server is IPv6 Ready

Most current server operating systems are ready to take the IPv6 leap. This includes Windows 2003 SP1 and most Linux OSes with 2.6.x Linux kernels. We’ll focus on Windows and RedHat/CentOS here.

To ready your Windows 2003 server for IPv6, do this:

1. In Control Panel, double-click Network Connections.
2. Right-click any local area connection, and then click Properties.
3. Click Install.
4. In the “Select Network Component Type” dialog box, click Protocol, then Add.
5. In the “Select Network Protocol” dialog box, click Microsoft TCP/IP version 6, then OK.
6. Click Close to save changes to your network connection.

Once IPv6 is installed, IIS will automatically support IPv6 on your web server. If a website was running when you installed the IPv6 stack, you must restart the IIS service before the site begins to listen for IPv6 requests. Sites that you create after you enable IPv6 automatically listen for IPv6. Windows 2008 server should have IPv6 enabled by default.

When your Windows server is ready for IPv6, you will add IPv6 addresses to the server just as you’d add IPv4 addresses … The only difference is you will edit the properties to the Internet Protocol Version 6 (TCP/IPv6) network protocol.

To ready your RedHat/CentOS servers, do this:

1. Using your favorite editor, edit /etc/sysconfig/network and enable NETWORKING_IPV6 by changing the “no” to a “yes.”

   Example:

   NETWORKING=yes
HOSTNAME=ipv6test.yourdomain.com
GATEWAY=10.13.40.1
NETWORKING_IPV6=yes
2. Next edit /etc/sysconfig/network-scripts/ifcfg-eth1 to add IPv6 parameters.

   Add the following to end of the file:

   IPV6INIT=yes
IPV6ADDR=YOURIPV6ADDRESS
IPV6_DEFAULTGW=YOURGATEWAY

   Example:

   IPV6INIT=yes
IPV6ADDR=2607:f0d0:2001:0000:0000:0000:0000:0010/64
IPV6_DEFAULTGW=2607:f0d0:2001:0000:0000:0000:0000:0001
3. Once you have successfully added your assigned IP addresses, you must restart networking with this command:
   [root@ipv6test /]# service network restart

Once you have completed these steps on your respective OS, you should be able to communicate over the IPv6 stack. To test, you can ping ipv6.google.com and see if it works.

3. Bind Your New IPv6 Address to Apache/IIS

Now that you have more IPv6 addresses for your server(s) than what’s available to the entire world in IPv4 space, you must bind them to IIS or Apache. This is done the similarly to the way you bind IPv4 addresses.

In IIS, all IPs that have been added to the system will now be available for use in the website properties. Within Apache, you will add a few directives to ensure your web servers is listening on the IPv6 stack … which brings us to a very important point when it comes to discussing IPv6. Due to the fact that it’s full of colons (:), you can’t just write out the IP as you would a 32-bit address.

IPv6 addresses must be specified in square brackets or the optional port number could not be determined. To enable Apache to listen to both stacks on separate sockets you will need to add a new “Listen” directive:

And for your Virtual Hosts, the will look like this:

4. Add Addresses to DNS

The final step in getting up and running is to add your new IPv6 addresses to your DNS server. If you’re using a IPv6 enabled DNS server, you will simply insert an ‘AAAA’ resource record (aka quad-A record) for your host.

5. Test Your Server’s IPv6 Accessibility

While your DNS is propagating, you can still test your webserver to see if it responds to the IP you assigned by using square brackets in your browser: http://[2101:db8::a00:200f:fda7:00ea]

This test, of course, will only work if your computer is on a IPv6 network. If you are limited to IPv4, you will need sign up with a tunnel broker or switch to an ISP that offers IPv6 connectivity.

After about 24 hours, your server and new host should be ready to serve websites on the IPv6 stack.

Good luck!

-Harold